<!doctype html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>
async_test(t => {
  window.onload = () => t.step_timeout(() => {
    let start_length = history.length;
    let start_index = navigation.currentEntry.index;
    let target_key = navigation.currentEntry.key;
    let target_id = navigation.currentEntry.id;
    location.hash = "#1";
    assert_equals(history.length, start_length + 1);

    navigation.onnavigate = t.step_func_done(e => {
      assert_equals(e.navigationType, "traverse");
      assert_true(e.cancelable);
      assert_true(e.canIntercept);
      assert_false(e.userInitiated);
      assert_true(e.hashChange);
      assert_equals(e.downloadRequest, null);
      assert_equals(new URL(e.destination.url).hash, "");
      assert_true(e.destination.sameDocument);
      assert_equals(e.destination.key, target_key);
      assert_equals(e.destination.id, target_id);
        assert_equals(e.destination.index, start_index);
      assert_equals(e.formData, null);
      // NavigateEvent sourceElement is still in development, so test whether it is available.
      if ("sourceElement" in e) assert_equals(e.sourceElement, null);
    });

    history.back();
  }, 0);
}, "history.back() fires the navigate event and sets hashChange when reversing a fragment navigation");
</script>
